1. Field of the Invention
The present invention relates generally to a writing tool including an openable decorative article at a shaft end. More particularly, the present invention relates to a writing tool such as a knock type ball pen, an ever-sharp pencil or the like including an openable decorative article at a shaft end wherein the decorative article can be opened and closed in synchronization with outward/inward displacement of a core.
2. Description of the Related Art
To allow an user to feel an interest in practical use of a writing tool, a proposal has been already made with respect to arrangement of a various kind of decorative article at a shaft end of the writing tool. Most of the conventional decorative articles are used in the fixed state while each decorative article is connected to a shaft member, whereby an user feels an interest as if he plays with a toy. Some of the decorative articles exhibit movement to a certain extent but this movement is such that it is induced by vibration of a spring attached to the decorative article or operation of a movable member incorporated in the decorative article.
In practice, an interest derived from practical use of the writing tool similar to an interest derived from playing with a toy is induced by dynamic variation of a decorative article disposed at a shaft end of the writing tool. In addition, it is desirable that movement of the decorative article is achieved in a single pattern and moreover it is preferable that operation of the movable member is performed without any contact with the decorative article. With respect to the conventional writing tool, it has been found that movement of the decorative article is simple and monotonous, resulting in an extent of interest to be pleasantly felt by an user being insufficient.